未设置iOS委托并返回nil（Swift）

当我试图设置一个委托时，我得到了零，并且无法理解为什么该委托没有正确设置

我有一个视图控制器

ListViewController

，我在其中添加了一个子视图，

musicPlayer

MusicLayer

是一个UIView，它有一些按钮，当单击时应触发

ListViewController

中的操作

musicPlayer

的设置如下：

protocol MusicPlayerControlsDelegate {
    func playPauseClicked()
}


class musicPlayer: UIView {

var myDelegate: MusicPlayerControlsDelegate?

//this should trigger function in delegate
@IBAction func playOrPause(sender: AnyObject) {    
    println(myDelegate?)
    myDelegate?.playPauseClicked()        
}

class ListViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, MusicPlayerControlsDelegate {

var musicControls:musicPlayer = musicPlayer()

override func viewDidLoad() {
    musicControls.myDelegate = self
}

//adds musicPlayer nib as a subview to ListViewController
@IBAction func playInApp(sender: AnyObject) {

    let bundle = NSBundle(forClass: musicPlayer.self)
    var playerSubview = bundle.loadNibNamed("musicPlayerSubview", owner: nil, options: nil)[0] as UIView
    playerSubview.frame = CGRectMake(0, self.view.frame.width + 79, self.view.frame.width, 200)

    self.view.addSubview(playerSubview)
}

func playPauseClicked() {
    println("Your delegate is working")
}

ListViewController

的设置如下：

protocol MusicPlayerControlsDelegate {
    func playPauseClicked()
}


class musicPlayer: UIView {

var myDelegate: MusicPlayerControlsDelegate?

//this should trigger function in delegate
@IBAction func playOrPause(sender: AnyObject) {    
    println(myDelegate?)
    myDelegate?.playPauseClicked()        
}

class ListViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, MusicPlayerControlsDelegate {

var musicControls:musicPlayer = musicPlayer()

override func viewDidLoad() {
    musicControls.myDelegate = self
}

//adds musicPlayer nib as a subview to ListViewController
@IBAction func playInApp(sender: AnyObject) {

    let bundle = NSBundle(forClass: musicPlayer.self)
    var playerSubview = bundle.loadNibNamed("musicPlayerSubview", owner: nil, options: nil)[0] as UIView
    playerSubview.frame = CGRectMake(0, self.view.frame.width + 79, self.view.frame.width, 200)

    self.view.addSubview(playerSubview)
}

func playPauseClicked() {
    println("Your delegate is working")
}

---

当我运行此命令时，

println（myDelegate）

是

nil

并且

println（“您的委托正在工作”）

从未被调用。关于如何解决这个问题有什么建议吗？

如果我正确理解您的设置，问题是您在一个从未出现在屏幕上的MusicLayer实例（实际上应该是带大写字母M的MusicLayer）上设置代理--您创建了该实例，但从未对其执行任何操作。您应该在playerSubview上设置代理，因为它是作为子视图添加的实例

@IBAction func playInApp(sender: AnyObject) {

    let bundle = NSBundle(forClass: musicPlayer.self)
    var playerSubview = bundle.loadNibNamed("musicPlayerSubview", owner: nil, options: nil)[0] as musicPlayer
    playerSubview.frame = CGRectMake(0, self.view.frame.width + 79, self.view.frame.width, 200)
    playerSubview.myDelegate = self
    self.view.addSubview(playerSubview)
}

---

请注意，我将downcast改为“as musicPlayer”而不是“as UIView”，否则当您尝试设置委托时，编译器会抱怨。

有时，您忘记了segue

if(segue.identifier == "YourSegueIdentifier"){
        let v = segue.destinationViewController as! YourViewController

        v.delegate =  self

    }

这句话很重要，因为如果你忘了它，它就不起作用了

v.delegate = self

---

非常感谢你，我花了很多时间在一个非常复杂的问题上，最终这就是我遗漏的东西